fix undefined error and make array observation more efficient
fix undefined error and make array observation more efficient

igorrKurr/smoke-and-mirrors,ssendev/smoke-and-mirrors,dukex/smoke-and-mirrors,html-next/vertical-collection,runspired/smoke-and-mirrors,html-next/vertical-collection,ssendev/smoke-and-mirrors,html-next/vertical-collection,igorrKurr/smoke-and-mirrors,runspired/smoke-and-mirrors,gordonbisnor/smoke-and-mirrors,gordonbisnor/smoke-and-mirrors,runspired/ember-radar,dukex/smoke-and-mirrors,runspired/ember-radar,aquamme/smoke-and-mirrors,aquamme/smoke-and-mirrors